Agricultural combines for harvesting corn or maize use devices called row units for separating the ears of corn from the stalk of the plant. Row units are disposed along the leading edge of the harvesting head that is attached to the combine vehicle itself. Row units typically include two forwardly extending rotating stalk rolls that (1) grasp the stalk of the corn plant, (2) pull it downward between them, and (3) pull the stalk loose from each ear of corn.
Stalk rolls have sharpened knife-like edges that extend the length of the stalk rolls to provide a good grip on the stalks of the plant. These edges enable the stalk rolls to grasp and pull the stalk downward. The stalk rolls are mounted on adjacent elongated rotating shafts that extend from the row unit gearbox.
Stalk rolls are typically constructed of several individual elongate components. These components are typically bolted together to form a complete assembly. See, for example, European patent publication EP 0 846 409 B1, in which two adjacent stalk rolls are mounted on two adjacent rotating shafts. Each stalk roll is formed of two half-cylinders that are bolted together with bolts that extend through both the stalk rolls and through the shafts on which the stalk rolls are mounted. The stalk rolls are fixed to the shaft with bolts that transmit torque from the shaft to the stalk roll.
In an alternative arrangement, the body of the stalk roll is made of a single piece of metal to which individual elongated edges are bolted. These edges typically extend the length of the stalk roll body. See, for example French patent publication FR 2784263 in which a central welded roll comprises three elongate plates that are welded together to which three elongate knife blades are bolted.
In another arrangement, the stalk rolls are fixed to the shafts with a tapered coupling and a bolt that is threaded axially into the end of the shaft to compress the tapered couplings together and thus fix the stalk roll to the shaft. See for example, European patent publication EP 0 852 109 B1.
One problem with these arrangements is the cost of manufacture and assembly. Several components must be manufactured and later bolted or welded together to create a stalk roll. Another problem is that the assembled parts can loosen and come apart.
It is an object of this invention to provide a stalk roll formed as a unitary body to thus reduce the cost of manufacture and assembly, it a further object to provide a stalk roll requiring only limited additional machining.